package com.filter;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

public class LoginFilter implements Filter {

    String[] ignores;

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse)resp;
        HttpSession session = request.getSession();

        String uri = request.getRequestURI();
        if(session.getAttribute("username") != null || isIgnore(uri)){
            chain.doFilter(request, response);//过滤链
        }else{
            response.sendRedirect("login.jsp");
        }
    }

    private boolean isIgnore(String uri){
        for (String str:ignores) {
            if(uri.indexOf(str) != -1){
                return true;
            }
        }
        return false;
    }

    public void init(FilterConfig config) throws ServletException {
        String ignore = config.getInitParameter("ignore");
        ignores = ignore.split(",");
    }

}
